This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A199869 #8 Feb 08 2025 22:34:42
%S A199869 1,0,1,9,5,0,4,6,3,9,3,1,5,1,7,6,3,5,2,8,8,2,8,4,5,3,7,8,6,5,5,2,7,1,
%T A199869 4,6,7,3,0,1,9,2,1,7,1,9,3,3,3,8,9,0,3,5,5,1,1,3,6,1,0,3,5,9,2,2,2,0,
%U A199869 5,9,0,9,0,2,5,4,9,0,5,0,4,6,4,0,4,7,9,8,6,3,3,3,1,6,5,7,8,6,1
%N A199869 Decimal expansion of x>0 satisfying 4*x^2-3*x*cos(x)=3*sin(x).
%C A199869 See A199597 for a guide to related sequences. The Mathematica program includes a graph.
%H A199869 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A199869 1.019504639315176352882845378655271467301921719333...
%t A199869 a = 4; b = -3; c = 3;
%t A199869 f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x]
%t A199869 Plot[{f[x], g[x]}, {x, -2, 2}, {AxesOrigin -> {0, 0}}]
%t A199869 r = x /. FindRoot[f[x] == g[x], {x, 1.01, 1.02}, WorkingPrecision -> 110]
%t A199869 RealDigits[r] (* A199869 *)
%Y A199869 Cf. A199597.
%K A199869 nonn,cons
%O A199869 1,4
%A A199869 _Clark Kimberling_, Nov 11 2011